Managing Highly Coordinative Substrates in Asymmetric Catalysis: A Catalytic Asymmetric Amination with a Lanthanum-Based Ternary Catalyst
摘要:
Full details of a catalytic asymmetric amination with a lanthanum/amide-based ligand catalyst system are described. A catalyst comprising La(NO3)(3)center dot 6H(2)O, (R)-3a and H-D-Val-V'Bu was identified to promote the catalytic asymmetric amination of nonprotected succinimide derivative 1 with as little as 1 mol % catalyst loading Mechanistic studies by various spectroscopic analyses and several control and kinetic experiments suggested that the catalyst components were in equilibrium between the associated and dissociated forms, and that the reaction likely proceeded through a La(NO3)(3)center dot 6H(2)O/(R)-3a/H-D-Val-O'Bu ternary complex. This catalyst system was also effective for asymmetric amination of N-nonsubstituted alpha-alkoxycarbonyl amides 7, hitherto unprecedented substrates in asymmetric catalysis, probably due to their attenuated reactivity and difficult stereocontrol, affording the amination products in up to > 99% yield and > 99% ee. The high catalytic performance and enantiocontrol of the reaction with highly coordinative substrates were achieved by the activation/recognition of the substrates exerted by coordination to lanthanum and hydrogen bonding cooperatively in the transition state.
Catalyst for aromatic C—O, C—N, and C—C bond formation
申请人:Yale University
公开号:US06562989B2
公开(公告)日:2003-05-13
The present invention is directed to a transition metal catalyst, comprising a Group 8 metal and a ligand having the structure
wherein R, R′ and R″ are organic groups having 1-15 carbon atoms, n=1-5, and m=0-4. The present invention is also directed to a method of forming a compound having an aromatic or vinylic carbon-oxygen, carbon-nitrogen, or carbon-carbon bond using the above catalyst. The catalyst and the method of using the catalyst are advantageous in preparation of compounds under mild conditions of approximately room temperature and pressure.
Arylation of diethyl malonate and ethyl cyanoacetate catalyzed by palladium/di-tert-butylneopentylphosphine
作者:Jeffrey G. Semmes、Stephanie L. Bevans、C. Haddon Mullins、Kevin H. Shaughnessy
DOI:10.1016/j.tetlet.2015.01.072
日期:2015.6
α-Arylated carbonyl derivatives are important structural motifs in many natural products and pharmaceutically active compounds. Although arylation of simple monocarbonyl compounds is a well-established methodology, metal-catalyzed arylation of β-dicarbonyl derivatives is significantly more challenging. The ability of β-dicarbonyl anions to bind to palladium in a κ2-O,O mode, rather than the κ1-C-bound
在许多天然产物和药物活性化合物中,α-芳基化羰基衍生物是重要的结构基序。尽管简单的单羰基化合物的芳基化是一种公认的方法,但金属催化的β-二羰基衍生物的芳基化更具挑战性。β二羰基的阴离子结合至钯在κ的能力2 - ø,ö模式,而不是κ 1 - c ^结合的模式键形成所需的,经常导致催化剂体系的失活。烯醇盐的C-结合形式可通过使用空间需求的配体来促进。在此,我们报告中指出,空间要求的二叔丁基丁基新戊基膦(DTBNpP)配体与Pd(dba)2结合为芳基溴化物和氯化物与丙二酸二乙酯的偶联提供了有效的催化剂。Pd / DTBNpP系统还催化芳基溴化物与氰基乙酸乙酯的偶联。
[EN] ASYMMETRIC MICHAEL AND ALDOL ADDITION USING BIFUNCTIONAL CINCHONA-ALKALOID-BASED CATALYSTS<br/>[FR] ADDITIONS ASYMETRIQUES DE MICHAEL ET D'ALDOL UTILISANT DES CATALYSEURS BIFONCTIONNELS A BASE DE CINCHONINE
申请人:UNIV BRANDEIS
公开号:WO2005121137A1
公开(公告)日:2005-12-22
One aspect of the present invention relates to quinine-based and quinidine-based catalysts. Another aspect of the invention relates to a method of preparing a derivatized quinine-based or quinidine-based catalyst comprising 1) reacting quinine or quinidine with 5 base and a compound that has a suitable leaving group, and 2) converting the ring methoxy group to a hydroxy group. Another aspect of the present invention relates to a method of preparing a chiral, non-racemic compound from a prochiral electron-deficient alkene or azo compound or prochiral aldehyde or prochiral ketone, comprising the step of: reacting a prochiral electron-deficient alkene or azo compound or prochiral aldehyde or prochiral 10 ketone with a nucleophile in the presence of a catalyst; thereby producing a chiral, non racemic compound; wherein said catalyst is a derivatized quinine or quinidine. Another aspect of the present invention relates to a method of kinetic resolution, comprising the step of reacting racemic chiral alkene with a nucleophile in the presence of a derivatized quinine or quinidine.
Catalytic Enantioselective C−C Bond Forming Conjugate Additions with Vinyl Sulfones
作者:Hongming Li、Jun Song、Xiaofeng Liu、Li Deng
DOI:10.1021/ja0511063
日期:2005.6.1
highly enantioselective catalytic conjugateaddition to vinyl sulfones. Promoted by readily accessible organocatalysts derived from C6'-OH cinchona alkaloid derivatives and under mild, air- and moisture-tolerant conditions, conjugateadditions of a wide range of alpha-cyanoacetates bearing either an alpha-aryl or an alpha-alkyl substituent to vinyl sulfones proceeded in excellent enantioselectivity and
在这篇通讯中,我们描述了第一个高度对映选择性催化共轭添加到乙烯基砜的开发。由衍生自 C6'-OH 金鸡纳生物碱衍生物的易于获得的有机催化剂促进,在温和、耐空气和耐湿的条件下,将带有 α-芳基或 α-烷基取代基的各种 α-氰基乙酸酯共轭加成到乙烯基砜以优异的对映选择性和高产率进行。因此,这种高效且操作简单的对映选择性 CC 键形成共轭加成为全碳四元立体中心的对映选择性构建提供了一种新的有用的方法。
Catalytic enantioselective conjugate additions with α,β-unsaturated sulfones
作者:Hongming Li、Jun Song、Li Deng
DOI:10.1016/j.tet.2008.11.054
日期:2009.4
development of a highlyefficient catalytic asymmetric conjugate addition to α,β-unsaturated sulfones. Utilizing practical bifunctional organic catalysts and involving air- and moisture-tolerant conditions, conjugate additions of a wide range of Michael donors to α,β-unsaturated sulfones proceeded in excellent enantioselectivity/diastereoselectivity and high yield. This efficient and operationally